5.4.1 Texinfo introduction

However, you don’t need to read those docs. The most important
thing to notice is that text is text. If you see a mistake in the
text, you can fix it. If you want to change the order of
something, you can cut-and-paste that stuff into a new location.

Note: Rule of thumb: follow the examples in the existing docs.
You can learn most of what you need to know from this; if you want
to do anything fancy, discuss it on lilypond-devel first.